Automatic drilling machine



my 5, w. c. vxNEs AUTOMATIC DRILLING MACHINE 3 Sheets-Sheet 2 Filed June l2. 1.91-5

'AT'TORNEY Juy 5, 1949u TTRNEY Patented July 5, 1949 UNITED STATrli PATENT OFFICE 2,475,342 Auron/inria naiLLING MACHINE Application .lune 12, 1946, Serial No. 676,217 In Great Britain June 26, 1945 4 Claims. 1

This invention relates to automatic drilling machines.

The object of the invention is an automatic drilling machine in which the indexing holding and ejecting devices can be easily adapted to different Work xtures.

According to the invention, the automatic devices for bringing and registering the work pieces successively into operative position and ejecting them and, where necessary, holding them, are operated without mechanical connection with the drilling spindle or connected moving parts, by electric circuits comprising contact devices operated by earns on a slow speed shaft mechanically connected with the feeding means of the drilling spindle. The fixed table of the drilling machine may support an indexing table operated electromagnetically and adapted to support the work piece fixture and an electromagnetically operated ejecting device attached to the fixed table. An electromagnetically operated registering device may be attached to the xed table and adapted to register the table, after indexing, into accurate position by pressure applied radially to the formed edge of the indexing table or fixture or to work pieces on the fixture. An electromagnetically operated holding device may be attached to the xed table, adapted to hold work pieces against being rotated by the drill. The slow speed shaft of the drilling machine may carry a cam for feeding the drill spindle and the cams controlling the electric circuits.

Other objects of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by way of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

In the drawings:

Fig. 1 is a vertical section through the head of the drilling machine, to some extent diagrammatic.

Fig. 2 is a horizontal section through the line 2-2 of Fig. 1.

Fig. 3 is a part vertical section through the line 3-3 of Fig. 2, showing the cam contacts.

Fig. 4 is a plan View of the indexing fixture.

Fig. 5 is a view of Fig, 4 from the left with part section through the line 5 5 of Fig. 4, and omitting the ejecting devices.

Fig. 6 is a half side elevation at right angles to the `line 3-6 of Fig. 4, showing the ejecting device, and

Fig. 7 is a wiring diagram of the electrical controls.

Referring to Figs. 1, 2, and 3, the spindle I of the drilling machine is journalled in a sleeve 2, which is adapted to slide downwards from the position shown in the guide 3 of the frame. Above the sleeve 2, the spindle I passes through a gear wheel 4 with a feather key and an extension of the gear wheel carries the driving pulley 5. The sleeve 2, is moved downwards, carrying with it the spindle I, by means of a rack 6 formed on the sleeve, which is engaged by a pinion 1 free on the stud 8. Fixed to the-pinion 1 by a common sleeve is another pinion 9 which engages a rack Ill formed on the lower edge of a bar I I. The bar I I, at its right hand end carries a roller I2 which bears against a cam I3 on the shaft I4. If the bar I I be moved to the left by the cam I3, it turns the pinions 9 and I and lowers the sleeve 2 and spindle I to feed the drill. The roller I2 is kept in contact with the cam I3 by a spring, not shown.

The gear wheel 4 engages a gear wheel I5 on a shaft I6. This shaft carries a worm II engaging a worm wheel IB free to turn on the stud I9. Fixed to the worm wheel I8 is a pinion 20 which engages a gear wheel ZI on the shaft I 4. An extension 22 of the shaft I4 carries three cams 23 adapted to operate electrical contacts 24 (Figs. 3 and 7).

From the above, it is seen that there is a high speed reduction from the -spindle of the drilling machine to the shaft I4, and that one revolution of this shaft determines a cycle of operation of the drilling machine during which the drill is fed downwards, and then brought up again, while three electric contacts are made and broken at times determined by the cams 23. While the cam I3 turns counterclockwise from the position shown, the feed of the drill is rapid till the point marked I3 reaches the roller I2; the drill is then entering into contact with the work; from the point I3 to the point 25, the feed is slow, the drill then cutting its hole; from the point 25 to the position shown, the return of the drill is again rapid.

Figs. 4, 5, and 6 show the indexing table which is held on the fixed table 26 (Fig. 5) of the drilling machine and carries the work pieces. The base 2l of the indexing table is adapted to turn on the stud 28 fixed to the table 26 and is provided with ratchet teeth 29. The teeth 29 are engaged by a ratchet 3l] -pivoted at 3| to the square portion 35 of a bar 32 fixed to the plunger 33 of a solenoid 34. The bar 32 is guided in blocks 36. A spring 3l (of which only a few turns are shown) bears against the square portion 35 and normally retains the bar 32 and ratchet 30 in the position shown in which the bar abuts on a stop 38. A spring 3S keeps the ratchet against the teeth 29. When the solenoid 34 is energized, the plunger 33, with bar 32 and ratchet 30, is drawn to the right bringing the ratchet 3U into the position shown in dotted lines, where it bears against a locking stop 49, which is omitted in the view of Fig. 5. This movement turns the lindexing table 21 clockwise through the space of one tooth 29.

The work holding plate 4l is fixed to the top of the indexing table 21 by studs 42 and, in the example shown, is arranged to take terminal posts of the form shown best in Fig. 6 at 43. These posts are to have a hole 44 drilled. rIhe centre of the drill is at 45, the drill guide 46 being broken away.

The stems of the posts 43 enterholes 41 in the plate 4I and their bodies t in scallops 48in-'the upper edge of the plate. The posts are fed into the plate 4I at the left, are drilled when reaching the point 45 andare ejected, as explained later with reference to Fig. 6.

Since the work pieces are circular, they have to be clamped against lturning when drilled and for this purpose a clamping lever 49 is pivoted to a post at 50, and its upper arm ends Ain a clamping finger I shaped to t the work piece. The lower arm carries the armature 52 of an electromagnet 53. The lever 49 is normally kept against the stop 5 4 'by a spring 55. When the magnet 53 is energized, the nger 5I is pressed against the work piece 43, clamping it against the scallop 48 of the plate 4I. The finger 5i also serves the purpose of accurately registering the position of the indexing table,l by turning it, if necessary, till the workpeceflts into the-curve of the finger.

In the case of work pieces `which are held against turning by reason of their form, the nger 5I is employed only to register the indexing table, being given -a V-Shaped end adapted to enter notches in the plate 4I.

vThe work pieces are ejected by a lever pivoted at 56, its lowerarm 58 being an armature adapted to be attracted by the magnet 51, while its other arm 59, is below the shoulder of the work piece 43. On the magnet 51 being energized, the upper Aor left hand arm 59 is jerked upwards, ejecting the work piece from the plate 4l. The lever 58, 59 is normally kept in thepo'sition shown by the spring 50 and stop 6|.

The cams 23 are arranged to energize the solenoid 34 and the magnets 53 and v51 through the conta-cts 24, as follows:

On the up-stroke of the drill spindle, the solenoid 34 is energizedr and the 4indexing table is turned to bring a work piece vinto the drilling position 45; the magnet 53 is then energized to clamp the work piece and register the table; the solenoid is then deenergized, but the magnet 53 is kept energized during the down-stroke of the drill and drilling period, and during the start of the up-strolre till the drill is out of the work piece, and is then deenergized; the magnet 51 is energized to eject the work piece at any time during the stationary period o'f the indexing table.

It is seen that there is no mechanical connection lbetween the drilling machine proper and the indexing, clamping and ejecting devices. It is, therefore, easy to make any alteration required for drilling Work pieces of different forms. Thus, a plate 4l is constructed to hold the pieces and is fixed to the indexing table; if the pieces are of a size larger than the pitch of the teeth 29, the cam for energizing the solenoid 34 may be arranged to energize it Atwice in rapid succession, so that the indexing table is moved through the pitch of two teeth at each operation; a different form of electing device can be fixed to the table 26 in place of the one shown. Again, the drilling period and rate of feed can be altered by changing the cam I3, and suitable times of operation of the devices on the table are determined by tting appropriate cams 23. Further, the revolutions of the drill per cycle can be varied by varying the .ratio of the gear wheels, 20 and The motor M, Fig. 7, of the machine is energized upon the closure of the main and button switches. Then, a moderated and rectified current is made available to the control devices, said current being influenced by passage through the transformer T and the rectifier R. Cam contacts 24 close at a time when the drill is raised, and then the solenoid 34 is energized to operate the ratchet and turn the work table through one tooth space. The circuit therefor includes wire 13, cam contacts 24, solenoid 34, and wires 1| and vlil back to the rectifier R.

Directly after the movement of the table and before the drill descends, the magnet 53 is energized and held in operation to detent the table and clamp the work piece which is to be operated upon. The energization of magnet 53 is timed by the closure of cam contacts'24. The circuit comprises wires 13 and T4, cam contacts v24, wire 15, magnet 53, resistances R2 and R3 and wires 12 and 10 back to the common rectifier R. Arrangedin shunt across contacts 24 are the con'- denser C and the resistance RI to prevent sparking at the contacts.

The othermagnet 51 is energized to eject the work piece at a time while the indexing table is stationary. Upon closure of cam contacts 24', a circuit is established including wire 13, cam contacts 24', magnet 51, resistance R4 and wires 1-2 and 10 to the rectifier R.

While there have been shown vand described and pointed out the fundamental novel features of the invention as applied to a preferred embodiment, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the following claims.

What is claimed is:

1. In a drilling machine with means for drilling work pieces on a rotating index table and having in combination, means for advancing said table step by step to present the Work pieces successively for drilling, a solenoid for operating said advancing means, means for energizing said solenoid between operations of drilling, a clamping means for holding said Work pieces on said table and for registering said table in position, a magnet for operating said clamping means, means for energizing said magnet vbefore the opera-tion of drilling and for holding said energization during drilling, an ejecting means for removing the work pieces from the table, a magnet for operating said ejecting means, and means for energizing said ejecting magnet as an incident to each drilling operation and while said table is stationary.

2. The combination set forth in claim 1 including a slow speed shaft operated continuously during drilling, three adjustably and removably mounted cams on said shaft, three pairs of cam contacts operated by said cams, and electrical circuits connecting each of said pairs of REFERENCES CITEH contacts as part of one of said energizing means to control drilling. The following referenices are of record in the 3. The combination set forth in claim 1 Wherefile of this patent: in said ejecting means includes an armature, a 5 portion of which is brought into cooperation with UNITED STATES PATENTS a work piece to jerk it away from the index table. Number Name Date 4. The combination set forth in claim 1, where- 1,786,034 Smith Dec. 23, 1930 in said clamping means includes an armature, a 2,303,243 Trythall Nov. 24, 1942 portion of which is formed to engage a work piece 10 2.381,9,668 Johnson Nov. 27, 1945 to hold it in position to be drilled and to prevent 2,394,769 Heckethorn Feb. 12, 1946 rotation.

WILLIAM CHARLES VINES. 

